A hangover lasts a lot longer than you think

You'll feel it in the morning — and the afternoon and evening, too.

You expect to feel rough first thing in the morning after a night of heavy drinking. But researchers who took a closer look at impairment long after the drinking was done, say that's just the beginning of the story.
(Photo: Fure/Shutterstock)

The common way to fend off the ill effects of a night of drinking — something researchers say you shouldn't do anyway — is to drink a lot of water and get a lot of sleep. With luck, you'll offset the worst of it and get on with your life.

"Our findings demonstrate that hangover can have serious consequences for the performance of everyday activities such as driving and workplace skills such as concentration and memory," Sally Adams, senior author and a lecturer of psychology at the University of Bath, said in a statement.

Too many drinks

Adams and her fellow researchers conducted a meta-analysis, or a study of studies, of researcher papers with the words "alcohol" and "hangover" in them. Ultimately, 11 out of 770 academic articles surveyed contained enough information to be included, along with 19 experimental studies that used hung over participants. Those experimental studies covered over 1,000 participants since the 1970s.

All the information from the studies regarding hangover severity, blood alcohol content (BAC) and cognitive performance were extracted from their respective works, and then Adams and her team calculated an estimate of the effects.

The results shouldn't surprise anyone who's had a hangover. Problems with long- and short-term memory were consistently found, along with the ability to maintain sustained attention. Psychomotor skills related to tasks that require movement and coordination, like driving, were similarly impaired. These effects could be observed even a day later.

"We found that hangover impaired psychomotor speed, short and long term memory and sustained attention. Impaired performance in these abilities reflects poorer concentration and focus, decreased memory and reduced reaction times the day after an evening of heavy drinking," said lead author and Bath Ph.D. student Craig Gunn.

In short: Even after alcohol has left your body, your body doesn't simply bounce back, good as new.

A dehydrating experience

The only way to avoid a hangover is not to drink. (Photo: AndreyCherkasov/Shutterstock)

The reason you body takes time to recover has to do with what alcohol does to your body, particularly your brain.

Alcohol inhibits the production of vasopressin, a hormone that stops you from urinating if your body determines it needs to hold onto water. If there's no vasopressin, your kidneys work overtime and you end up having to urinate a lot. This is why even if you're attempting to match alcohol with water to head off the effects, you're really just lowering the severity of the dehydration, not balancing out the alcohol.

Your organs, at this point, are drawing in as much fluid as they can to keep functioning, and this can take away fluid from your brain. The dura, the membrane that surrounds our brain, shrinks due to the loss of water in the body. It's what causes the headache you experience during a hangover.

While you're urinating, you're also washing out nutrients your body needs, according to Forbes, and these nutrients — including magnesium, potassium and sodium — help with your cognitive functions.

The dura doesn't immediately grow back to its proper size after the alcohol has left your body, and those nutrients need to be replenished as well. This is why the effects of alcohol linger on — long after you've taken your final sip for the night.